Cutting REST-EN results in avrdude: stk500_getsync(): not in sync: resp=0x00

I cut RESET-EN so the arduino uno smd does not reset when the serial connection gets closed.

Now every time I try to upload a sketch I get the error;

avrdude: Send: 0 [30]   [20] 
avrdude: Send: 0 [30]   [20] 
avrdude: Send: 0 [30]   [20] 
avrdude: Recv: 
avrdude: stk500_getsync(): not in sync: resp=0x00

avrdude done.  Thank you.

I can get a sketch to upload correctly if I press the reset button during the upload process.

My understanding is that trick is typically used when the arduino is sending too much over serial to have a sketch loaded.

I need to do the reset trick every time even when the blink sketch is currently loaded and trying to upload the blink sketch.

I thought I might have damaged the arduino so I cut the RESET-EN on a second arduino with the same result.

By cutting the Auto Reset Enable jumper you have disabled the Auto Reset feature. The only way to upload when Auto Reset is disabled is to manually reset. Perhaps you could put a pair of pins where the Auto Reset Enable jumper was and jumper those pins when you want to upload.

My understanding is that you need to reload the arduino after uploading a new sketch not that you need to do a well timed reset while uploading the sketch.

With RESET-EN cut I need to release the reset button when I see the first "avrdude: Send: 0 [30] [20]" to successfully upload a sketch.

bigmagu:
With RESET-EN cut I need to release the reset button when I see the first "avrdude: Send: 0 [30] [20]" to successfully upload a sketch.

That is correct. The processor needs a reset by the reset-en or the reset button to start the bootloader. You have chosen to disable the auto reset, so now you must do that manually with the reset button.

You can add some solder across the pads to re-enable the reset.

Or add a real jumper / switch. The way it should have been in the first place.